Methods of modifying the energy of a substrate using a plasma are already known.
United States patent application US 2007/0269883 (ULRICH) relates to a method of localized modification of the surface energy of a substrate in which a pad having through channels is brought into contact with a substrate, giving rise to localized treatment of the surface due to the fact that the radicals derived from the plasma can penetrate via the ends of the channels and treat the surface locally.
Similarly, United States patent application US 2006/0116001 (WANG) proposes raised patterns on a pad acting as a mask so that portions of the substrate that are left uncovered can undergo an energy modification treatment such as exposure to a plasma.